Date: Sat, 3 Jan 1998 10:20:29 -0800 (PST) From: Kevin McQuiggin <mcquiggi@sfu.ca> To: bugs@freebsd.org Subject: Bug Report in getty Message-ID: <199801031820.KAA02422@fraser.sfu.ca>
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Hi FreeBSD:
I would like to report a bug, and bug fix, for FreeBSD 2.2.2.
This was located in /usr/libexec/getty, and is associated with the
gettytab :ac and :ic "chat scripts". See man gettytab for the functionality
of these scripts.
Here's the problem:
A gettytab entry of:
# TNC entry, create 97.12.31 by K. McQuiggin.
tnc|tnc.1200|1200-baud TNC:\
:ac=*** HI\sfrom\sgettytab\r:\
:de=1:\
:ct=1000:\
:np:sp#1200:\
should wait on the associated /etc/ttys line:
ttyd1 "/usr/libexec/getty tnc.1200" unknown on secure
for the string "***", then reply with the string "HI from gettytab" prior
to displaying the login: prompt. Here's what actually was produced:
("***" is typed, not echoed)
HI sfro \sgettytab
FreeBSD (sputnik.rfnet.sfu.ca) (ttyd1)
login:
Note how the quoted spaces ("\s" according to man gettytab) are not interpreted
properly. The correct result should appear as:
HI from gettytab
FreeBSD etc...
Obviously there is something wrong with the way that these literal characters
are being interpreted! This was found to be a problem for all of the escaped
special characters noted in the man page.
I looked at the source code and noted the following statements starting at
line 224 of /usr/src/libexec/getty/chat.c:
} else {
/* copy standard character */
*r++ == *q;
}
This "==" looked incorrect as an assignment and I changed it to:
} else {
/* copy standard character */
*r++ = *q;
}
And now the :ac output is correct:
("***" is typed, not echoed)
HI from gettytab
FreeBSD (sputnik.rfnet.sfu.ca) (ttyd1)
login:
I have tested the other backslashed special characters and this looks to
be the fix.
I suggest that this fix should be added to the getty source for the next
release, if it hasn't been changed already!
I have located another problem with the gettytab entries for these characters
which I will report separately. In a nutshell someone is pre-parsing the
:ac and :ic scripts prior to them getting to chat.c, so that \s for example
is being replaced by just s prior to chat.c seeing the input string.
I got around this by double backslashing the chars in gettytab:
HI\\sfrom\\sgettytab
This too is no to the spec and I'll see if I can find out what's going
wrong and report it.
Please reply to me via email, I read freebsd-questions infrequently as there's
too much volume and my other mail gets lost in the noise!
I've used FreeBSD for about 3 years, it's fantastic, keep up the good work!
Kevin
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